1. Field of the Invention
The present invention relates to a semiconductor package and, more specifically, a stack land grid array package and a method for manufacturing the same.
2. Description of the Related Art
In general, land grid array packages include a substrate, a semiconductor die attached to the substrate, a connection member for connecting the substrate and the semiconductor die, an encapsulant for encapsulating the semiconductor die and the substrate, and lands formed on a surface of the substrate to allow the package to be mounted on an external device. The land grid array packages have reduced manufacturing cost, because the lands (not solder balls) are directly mounted on an external device and a process for thermally bonding solder balls can be omitted from the manufacturing processes.
Recently, companies have begun to stack a number of semiconductor dies inside a single semiconductor package or stack a number of semiconductor packages on one another so that electronic products incorporating them have a larger capacity and more functions. However, above-mentioned conventional land grid array packages have a problem in that it is difficult to stack a number of semiconductor dies on a single substrate. This is because a semiconductor die is attached to a surface of the substrate and a number of lands are formed on the other surface thereof. The fact that the semiconductor dies can only be attached to one of two surfaces of the substrate makes stacking multiple dies difficult. It may be possible to stack a semiconductor die on another. However, this requires that the adhesive interposed between the semiconductor dies have a thickness large enough to preventing conductive wires connected to the lower semiconductor die from sweeping or short-circuiting. In addition, the adhesive must have a low elastic constant and excellent degree of flatness so that conductive wires can be easily connected to the upper semiconductor die. As such, very expensive adhesive is necessary for stacking between the semiconductor dies.
Furthermore, conventional land grid array packages having lands formed only on a surface of the substrate cannot be stacked in large numbers along the vertical direction. In order to stack a number of land grid array packages, a number of lands must be positioned on both surfaces of the substrate while being exposed to the exterior. However, the substrate of conventional land grid array packages has an encapsulant completely encapsulating a surface thereof and a number of lands formed on the other surface thereof. Such a construction makes it impossible to stack the packages in large numbers.
Therefore, a need existed to provide a stackable land grid array package and a method for manufacturing the same.